Adhesive



.too, may be :changed Patented Mar. 24, 1931 UNITED STATES PATENT OFFIC ADOLF MENGER, F KREFELD-BOCKUM, GERMANY, ASSIGNOR TO I. G. FARBENIN- DUSTIR IE AKTIENGESELLSCHAFT, OF FRANKFORT-ON-THE-MAIN, GERMANY, A COR- PORATION OF GERMANY ADHESIVE No Drawing. Application filed August 2, 1928, Serial No. 297,123, and in Germany August 10, 1927.

The invention relates to adhesives and in particular comprises adhesives containing a cellulose ester as fundamental constituent.

vThe known adhesives composed of a cellulose ester, a plasticizing and/or a softening agent and a solvent or solvent mixture there- I for are not able to stick leather, felt, textile fabrics or the like to a smooth, say,-a metallic surface unless the latter has beenconsiderably roughened. lVithout preliminary roughening of the originally smooth surface the adherence of the objects to be stuck together is quite insufiicient and in many cases roughening is impossible on account of the slight strength of the metallic surface.

I have found that the adhesive power of adhesives containing a cellulose ester as fundamental constituent and especially the adherence of such solid substance to the adhesive composition, in a finely divided state. In particular the addition of a finely divided filler having a fibrous structure has proved useful. Among the substances suitable for the purpose of my invention I mention: -metallic powders (bronzes), saw dust, kaolin, talcum, flour,

asbestos, etc. These substances are added to the adhesive cellulose 'ester composition in an amount of percent and more (calculated to the adhesive composition). The composition of the adhesives which are mixed with the above-mentioned fillers may var within wide limits and the quantity of fillers,

to suit varying conditions. In all cases the adhesives containing a certain amount of fillers especially fillers of fibrous structure are excellently suitable to stick porous absorbent substances such as leather, smooth surfaces e. g. metallic surfaces.

I prefer to add to my solutions ethyl acetanilide which acts in a similar manner as, for instance, camphor or the well-known camphor substitutes.

adhesives to smooth sur- K faces is considerably increased byadding a felt, textile fabricsand the like to In order to illustrate my inventionI give- The parts are by weight.

, Parts Nitrocellulose Camphor 6 Acetone 79 Saw dust 10 (:2) Parts Acetyl cellulose 12 Tricresyl phosphate 8 Methyl alcohol 20 Ethyl acetate 30 Methyl acetate 3O aolin 25 Parts Nitrocellulose 16 Ethyl acetanilide 10 Acetone Y 74 Asbestos finely ground Parts Waste photographic films Ethyl acetate. 60 Ethyl alcohol 20 Aluminium bronze 10 (5) Parts Nitrocellulose 12 Ethyl acetanilide 4. Castor oil L 2 Ethyl acetate 20 Methyl acetate i 20 Methyl alcohol 17 Asbestos finely ground Parts Waste photographic films 14 Ethylacetanilide 2 oil, 57 parts of a solvent therefor and parts 011 ,of ground asbestos. y p p In testimony whereof I have hereunto set Ethyl aceta 13 my haml Met y acetate 13 ADOLF MENGER. Methyl alcohol 6 Acetone 21 Gasolene 6 Asbestos ground and levigated 20 Parts Nitrocellulos 1 Camphor 4: Tricresyl phosphate 2 Acetone 50 Butyl acetate; 20 Saw dust Y 1 14 In order to illustrate more fully the application of the new adhesives I give further some recipes for sticking porous substances to metallic surfaces:

(a) Sticking leather to iron An adhesive in accordance with one of the foregoing examples, say Nr, 5, is brushed upon an iron sheet carefully cleansed and allowed to dry for 24 hours. The leather is brushed with any wellknown cellulose ester adhesive, allowed to dry (which requiresabout 2 hours) and then pressed to the iron sheet which was previously wetted by the same cellulose ester solution spread over the leather. After an hours pressing the stuck ob'ects are permitted to completely dry at inary pressure.

(1)) Sticking wood veneer to The aluminium sheet carefully cleansed is brushed with an adhesive, say, according to Example 5 and allowed to dry for 24 hours and both are further treated as follows:

(a) The aluminium sheet is wetted with a known cellulose ester adhesive or a solvent capable of dissolving cellulose esters and pressed to the wood, or I a (,8) The aluminium sheet and the wood are pressed together in a heated ress for an hour at about 100 C. The woo slightly roughened is coated with a known cellulose ester adhesive without fillers.

-Iclaim:

1. A viscous adhesive composition of high sticking power comprising nitrocellulose, ethyl acetanilide and a softening agent and a solvent therefor, containing at least 10% of 3. A'viscous adhesive composition comprising about 12 parts of nitrocellulose, 4 parts of ethyl acetanilide, 2 parts of caster 

